ok, so i'm in a hotel room. i've got my wifi turned on and noticed that someone who is using a mac (assuming the ssid is genuine) is openly advertising their ad-hoc wifi connection with no authentication/encryption. i can associate with their machine, and my pc autoconfigures an address. i've tried pinging the broadbast address of the autoconfigured subnet to see if i get an ip/mac in my local arp cache for the machine - but nothing. is there any way i can connect so i can get a message to them to tell them to secure their damn wifi connection?! normally i wouldn't be remotely bothered, but i'm down here on a wifi course, so i kinda have a vested interest to try and be a good samaritan!